Alert archive / Louisiana / Flash Flood Warnings in 2020

Flash Flood Warning 30, NWS New Orleans, LA

October 23, 2020Lafourche Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Oct 23, 2020, 3:40 PM CDT for Lafourche Parish, Louisiana. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 23, 2020, 3:40 PM CDT (20:40 UTC)
Expired: Oct 23, 2020, 6:03 PM CDT
In force: 2 hr
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

County Lafourche Parish, LA

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 8.7 hours before the alert went out and 315 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 591 J/kg
Mixed-layer CIN: -75 J/kg
Mixed-layer LCL: 853 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New Orleans, LA wrote its last area forecast discussion before this flash flood warning went out at Oct 23, 3:28 AM CDT, 12 hours 12 minutes earlier.

Area forecast discussion, Oct 23, 3:28 AM CDT, 12 hours 12 minutes before

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In the hours before

Special weather statement, Oct 23, 2:09 PM CDT, 1 hour 31 minutes before

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Special weather statement, Oct 23, 2:11 PM CDT, 1 hour 29 minutes before

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Special weather statement, Oct 23, 2:48 PM CDT, 52 minutes before

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      <h1 id="headline">This service is currently unavailable.</h1>
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The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 23, 2:09 PM CDT	Special Weather Statement	LIX	Saint Tammany	66 min
Oct 23, 2:11 PM CDT	Special Weather Statement	LIX	Assumption	64 min
Oct 23, 2:48 PM CDT	Special Weather Statement	LIX	Ascension, Saint James	57 min
Oct 23, 3:00 PM CDT	Areal Flood Advisory	LIX	Ascension, Assumption, Iberville, Livingston, Saint James	2 hr
Oct 23, 4:59 PM CDT	Special Weather Statement	LIX	West Feliciana	46 min
Oct 23, 5:16 PM CDT	Special Weather Statement	LIX	East Feliciana	44 min
Oct 23, 5:29 PM CDT	Areal Flood Advisory	LIX	East Feliciana, West Feliciana	2 hr
Oct 23, 6:01 PM CDT	Special Marine Warning	LIX		44 min
Oct 23, 6:17 PM CDT	Special Weather Statement	LIX	Pointe Coupee	43 min
Oct 23, 6:19 PM CDT	Special Weather Statement	LIX	Jefferson	41 min
Oct 23, 6:51 PM CDT	Special Weather Statement	LIX	Pointe Coupee, West Feliciana	39 min
Oct 23, 5:59 PM CDT	Special Weather Statement	LIX	Wilkinson	46 min

Nearby

Flash Flood Warnings in Louisiana, 2020 Every flash flood warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.